Horticulturists are professional gardeners with an academic degree who are trained in horticulture, gardening, and land management (other related degrees include landscape design and landscaping, which are often distributed by a university's horticulture department).

"Gardening," is also used as slang to refer to smoking weed, and a "gardener" is someone who does this while the "garden" is related to marijuana due to people often calling the drug "plant," "bud," and "trees."

The purpose of gardening intensively is to harvest the most produce possible from a given space. More traditional gardens consist of long, single rows of vegetables spaced widely apart. Much of the garden area is taken by the space between the rows. An intensive garden minimizes wasted space.

Professional gardeners have extensive knowledge about plants, pests, lawns, soil and ecology. They can instantly spot the difference between a plant and a weed.